1. Field of the Invention
The invention relates to a tufted backing and a method of manufacturing a tufted backing from thermoplastic polymer fibers or filaments processed into a spunbonded nonwoven.
2. Description of Related Art
European Patent Application 79 56 37 A describes the use of nonwovens of polyester and copolyester fibers as a tufted backing for tufted carpets reinforced by parallel, straight, load-bearing continuous plastic fibers. Despite a mass per unit area of only 80 to 150 g/m2, this measure should yield a tufted backing which is resistant to the effects of stress, temperature and moisture in dyeing, tufting and steaming during manufacture and processing to yield tufted carpets, in particular with regard to lateral shrinkage.
In addition, a nonwoven for coating carpet backings is known from German Utility Model 94 11 993, where the bonded elementary fiber nonwoven having a mass per unit area of 20 to 220 g/m2 is reinforced by a maliwatt method with warp threads of film ribbons. This should improve foot comfort, the connection to the carpet weave, the shape of the carpet and its recyclability.
German Patent Application 195 01 123 and German Patent Application 195 01 125 describe a method which results in a greater strength of the nonwoven in both longitudinal and transverse directions due to a stretching operation in the stretch range of 100% to 400% and reduces both the elongation and the residual shrinkage. Preferably, however, the mass per unit area of the nonwoven webs is to be reduced at preselected values for their elongation and residual shrinkage. However, the stated degree of stretching in combination with the resulting stretching of the fibers themselves results in a significant restriction of the mobility of the fibers in the nonwoven, so that the tufting process is impaired.
Japanese Patent Application 10-273865 describes tufted backings made of continuous filaments of a thermoplastic synthetic resin and having a thermal shrinkage in transverse direction with dry heating in the range of −10% to 0%, measured according to JIS L 1906. The tufted backings are constructed of a high-melting component and a low-melting component.
International Patent 96/29460 describes tufted carpets composed of a tufted backing and an adhesive binder. The binder should preferably be a thermoplastic polymer which is applied to or bonded with the tufted backing.